Surgical procedures are often performed in surgical fields which are of a limited size or beneath the skin. With respect to endoscopic procedures, there are several methods for viewing the body interior. For example, the surgeon may look directly through the eyepiece of the endoscope. Alternatively, a beam splitter may be used to provide a second eyepiece for a surgical assistant to simultaneously view the surgical field. For those instances where more than two simultaneous views are necessary, the second view is replaced with a video camera. Splitting the beam between the eyepiece and video camera allows the surgeon to view the surgical field in a high resolution display while the video camera and monitor allow the remaining members of the surgical team to view the procedure. Alternatively, a video camera is mounted directly to the endoscope and one or more monitors are located about the operating environment so that the surgical team may view the field.
Alternatively, liquid crystal display (LCD) monitors can be employed. However, the LCD monitors have a limited viewing angle and an LCD having a sufficient size to permit sufficiently high resolution creates a substantial intrusion to the operating environment. In addition, the LCD monitors are nondisposable, thereby creating a sterilization problem. Further, the accompanying electronics and wires add undesired clutter to the operating environment.
Standard video projection systems are also used. However, the video projecting systems require the screen to be perpendicular to the projection axis. Therefore, locating the display screen at an optimum viewing angle causes a portion of the projected image to be out of focus. Alternatively, the projection path excessively interferes with the operating environment and is subject to frequent interruptions. Further, standard projection screens are irreparably stained by blood and bodily fluids, while disposable flexible screens require stretching or sufficient tension to retain the screens in a proper orientation.
The disadvantages of the prior systems include disorientation created by locating the monitor or projected image of the surgical field remotely from the surgical field. This disorientation is enhanced by the surgeon being unable to view the area of the surgical field and their hands simultaneously. In addition, forcing the surgeon to focus on an image at a relatively large distance while the surgeon's hands are adjacent the body is an unnatural perspective detrimental to the efficiency of surgeons. In addition, constraints on the available locations of the video monitors relative to the surgical field are such that the direction of movement of an instrument within the surgical field is often not translated into a movement in the same direction in the projected image.
Therefore, a need exists for a video display system for an operating environment, wherein a high resolution projected image of a surgical field or other video information may be located adjacent the surgical field and in a viewing orientation which is optimal to the surgeon. In addition, the need exists for a video display system which presents an image which is consistent with the direction of movement within the surgical field. The need also exists for a disposable and/or sterilizable screen for permitting contact with the surgical team, or blood and other bodily fluids during the surgical procedure. The need also exists for a viewing screen which may be located at a favorable viewing angle without jeopardizing the integrity of the projected image.